The 1972 tube stock was a minor evolution of the 1967 stock that was ordered for the Victoria line. The first batch (MkI) were for the Northern Line to replace 1938 stock. The second batch (MKII), while intended for the new Fleet (now Jubilee) line worked on the Northern until the former opened in 1979. Subsequently displaced by the 1983 stock the 72mkII replaced the '38s on the Bakerloo line, where they have remained to this day.

The cars were built by Metro-Cammell, a political order to save the company. There were thiry-three trains built, each of seven cars. These were joined on the Bakerloo line by some of the MkIs and the line-fleet is currently thirty-six trains. As with all Underground trains, they run on the 630v fourth rail system.

This is my second tube train model; the stock was chosen because it is, visually at least, the archetypal tube train. As with my other tube stock models the motor is hidden beneath a skirt on one of the cars. The design was challenging, as the offset doors cut into the body which creates complications with the structure of the car bodies as the strength had to be focused though the roof and a central section of the floor down each car, while at the same time attaching the doors securely.

The cars are joined by tow-balls and -sockets which makes the cars appear more semi-permanently coupled and realistically spaced apart. However, to actually run, they require replacing with magnetic couplers which add the necessary second hinge point to the couplings and space the cars out further for the curves of the track, which has been done on this model recently and will be retrofitted to all other tube stocks in the near future.

This model was first displayed at the Milton Keynes Lego Brand Store in the summer of 2006 and has since been displayed at the Brickish Association 2006 LLW Christmas Party, 2007 AGM, Petersfield Lego Show and Merrist Wood and Twyford Lego displays .